1980 GS550 not firing on cylinder 1

[Guest]

I have recently been able to get my bike running at last, though it is having trouble starting from a cold start. Once I get it going it idles, throttles, and goes just fine... it will even start up again once I shut her down (5 minutes of cooling)

All of this is exciting for me because I haven't been able to get her to do anything since I got her-- carbs removed and cleaned 3 times, intake boots replaced due to severe cracking, air filter and airbox boots taken care of, and fuel petcock replaced.

Unfortunately, after opening up the throttle for a bit (4k-6k RPMs) and pulling the plug on cylinder 1 she is wet and the exhaust is only heating up due to heat transfer. Myself and a second opinion were able to discern that fuel is getting into the cylinder due to the smell and the plug.

My question is this: How likely is it that the plug wire for cylinder 1 is shot? And can anyone help me understand how to acquire a replacement-- I see a lot of "universal" plug wires, but I am uneducated on the subject and have no idea if the ignition system requires something particular.
If anyone can point me in the right direction here, I'd be very grateful.

Thanks for any help!

[tom203]

If you think it's a plug wire issue, just switch the plug leads on 1 and 4 and see if your issue moves to #4.
Or remove plug caps and cut back plug wires about 1/4 inch each.
But it sounds like it might be a float needle seat issue.... Too much fuel overfilling bowl and overwhelming #1 cylinder when main jet is in play

[Celilo]

I will do a quick test with swapping the plug wires-- I was digging through the shop manual and did notice that 1 & 4 were the same timing, so I was wondering if that were possible.

If it is a float needle seating-- it could be as simple as adjusting the float height, correct? Assuming all other parts are in good repair. To my understanding it is a task to remove the floats themselves, usually requiring unbenching the carb to accomplish it?

[tom203]

[QUOTE=Celilo;2419271.......
If it is a float needle seating-- it could be as simple as adjusting the float height, correct? Assuming all other parts are in good repair. To my understanding it is a task to remove the floats themselves, usually requiring unbenching the carb to accomplish it?[/QUOTE]
Yes, but you already were supposed to have done this, since you said...

"carbs removed and cleaned 3 times, ". Probably best to explain your carb cleaning method, as these carbs don't respond well to quickee techniques.

your fuel height could be set wrong, the o-ring under the needle seat could be damaged, the float might be sticking on bowl gasket,etc

[Redman]

When you are thinking "plug wires", do not overlook the plug caps. They should check at about 5k ohms. THey do go bad (high resistance) over time and heat and miles, and are eaasy replaceable, and are only about $5 each. THe stock wires are a lot harder to replace.

THe caps just twist and pull off of the wire. THen check with an ohm meter. Or maybe swap to other cylinder.

.

[Celilo]

I gave 1 and 4 the swap and it didn't transfer the problem.

I did, however, get my **** shocked when touching #2 cylinder plug cap. I didn't get enough time to check all of them before my neighbor was hollering about starting my bike at 930am.

[Redman]

I gave 1 and 4 the swap and it didn't transfer the problem.

I did, however, get my **** shocked when touching #2 cylinder plug cap. I didn't get enough time to check all of them before my neighbor was hollering about starting my bike at 930am.

The bikes exhaust....? Or you hollering from getting shocked...? har har har

You swapped the wire/cap from 1 to 4...?
Now try swapping the plugs.

.

[Celilo]

The bikes exhaust....? Or you hollering from getting shocked...? har har har

You swapped the wire/cap from 1 to 4...?
Now try swapping the plugs.

.

Haha. I wish the exhaust was hot, alas it was just electrical shock.

I previously rotated the spark plugs and pulled them after running the bike for 10 minutes. The plug from 1 fired just fine in C4 and C2.
When plug C1 was pulled it was wet and dark-colored all the way up inside it. It was clear that it was not firing, and it the smell of gas is strong.
When plug wires C1 & C4 were swapped I didn't notice a problem with C4. I didn't get to run the bike very long due to a whiny neighbor, but I could tell the exhaust was heating up. C1 still was cool.

At this point, I am leaning toward Tom's suggestion that it's an excess of fuel in the float bowls due to my negligence in checking float heights.
Before I pull the carbs once again I will turn over each plug to insure that the wires are sending good spark to eliminate that issue. It could be a good idea to get new caps anyway.